Gavran's latest activity

My condolences to the family. Could we at least have a picture of him during his happy days? That is the only way his memory can live on...

Two techniques should be applied in this case. The first one is the substitution as proposed in post #2, and the second one is the...

##u=x^2+\pi +1##

The question is a bit odd. Presumably, the bar does not get lifted off the surface, so that we have an assumed constraint of motion in...

Dealing with a dual vector space lacks bilinearity. It is more natural to use an inner product when we want to define lengths...

Thanks for the replies, Gavran and Wrobel. First, Gavran. That is good to hear. Could you give me an example of each, and why? (That...

There is a difference. The difference lies not only in the fact that an inner product is bilinear and a dual space operation is linear...

This is a periodic back-and-forth motion, and ## s ## is the distance of the moving bar from its initial position. Why do you expect ##...

The author says, “It follows that if α+β equals two right angles (that is, a straight angle) then l and m do not meet.” and he keeps on...

The author is right. It is all about “if and only if”. The parallel axiom includes “⇒” and it does not include “⇐”. “⇐” is included by...

See the images below. Both functions are automorphisms.

There is an interesting definition that can help. A rigid set is a set with the identity function as its only automorphism.

https://ceramicartsnetwork.org/ceramics-monthly/ceramics-monthly-article/quick-tip-reconstituting-clay

Great. The formula can also be written in the form of ## (10_d-1_d)\cdot11_d\cdot11_d ##.

Interesting. In general case of base-d system, the result value is ## d^3+d^2-d-1=(d-1)(d+1)^2## For 2-digit it is ##(d-1)(d+1)##